Pyrotechnic composition



PYROTECHNIC COMPOSITION Leonard D. Jackson, Alexandria, Va., assignor to the United States of America as represented by the Secretary of the Navy No Drawing. Application May 27, 1952,

Serial No. 290,377

4 Claims. (Cl. 52-23) (Granted under Title 35, U. S. Code (1952), see. 266) This invention relates to a pyrotechnic mixture and more particularly to a composition of matter for use in a signal flare, incendiary and self destroying devices such, for example, as the type employed by the armed forces.

The composition of matter of the present invention is characterized by low sensitivity whereupon it is safe during handling and transportation, will not explode, nor is it sensitive to blows and friction, all not ignite spontaneously, is stable against atmospheric changes and will burn violently under water. The mixture also possesses other admirable characteristics such, for example, as high candle power and intensive heat producing qualities.

Heretofore pyrotechnic compositions used in signal flares incendiary missiles and the like have not been altogether satisfactory for the reason, that such compositions were sensitive to blows and friction, unstable against atmospheric changes, lack the essential characteristics of high candle power and high temperature when ignited and during burning thereof.

The present invention is especially adapted to overcome the aforesaid disadvantages encountered heretofore and to provide a mixture in which the stability, candle power, and degree of heat has been greatly improved and in which the mixture is characterized by low sensitivity.

An object of this invention is to provide a new and improved pyrotechnic mixture for use in a signal flare or the like which is economical to manufacture, safe during handling and transportation and which produces a flame of great brilliancy and heat of a high degree during combustion thereof.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description.

The composition of the present invention possesses the desired characteristics which make it admirably suited for the use indicated herein and comprises a mixture of strontium nitrate as a fuel and boron as a heat producing agent it being understood, however, that the percentage of the strontium nitrate and boron may be varied to suit the particular requirements for which the mixture is to be used.

The ingredients of the composition described above may be varied within the following limits:

ner and if desired, may be, molded into any suitable form or pressed loaded into a suitable container such, for example, as a container composed of steel, plastic,

2,790,339 Patented June 18, 1957 magnesium, paper or the like. During pressure loading of the mixture into a container it has been found that the mixture is self-binding and thus it will consolidate to form a compact mass without the use of a binding agent. Furthermore, the strontium nitrate composition of matter furnishes ample fuel to cause the mixture to burn uniformly and with a considerable amount of brilliancy, it being understood, however, that by varying the proportions of strontium and boron the burning rate, candle power and degree of temperature may be varied. For example, excellent results have been obtained from a composition consisting of from to 65% of strontium nitrate and from 20 to 35% of boron and a composition consisting of from to 60% of strontium nitrate and from 15 to 40% of boron.

While the mixture of the present invention is characterized by low sensitivity it can be readily ignited by the conventional quick match whereupon it will burn with a brilliant flame and a great amount of heat of sufficient intensity to cause metallic material such, for example, as steel or the like to melt. Furthermore, the sensitivity of the composition is of such a low order that it may be drilled or chiseled with reasonable safety.

It has been found by actual tests that the mixture will burn violently when submerged in a body of water and thus it is admirably suited for use in an incendiary bomb or the like whereupon a quantity of oil either on land or the surface of a body of water may be ignited thereby.

From the foregoing description it will be apparent that a pyrotechnic mixture for use in a signal flare, incendiary bomb or the like has been compounded which is economical to manufacture and in which the burning rate, candle power and heat producing characteristics thereof have been greatly improved, the mixture being further characterized by low sensitivity whereupon it is safe during handling and transportation.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A pyrotechnic mixture for use in an incendiary device consisting of from 80 to 65% of strontium nitrate and from 20 to 35% of boron.

2. A pyrotechnic mixture for use in an ordnance missile and characterized by low sensitivity, high candle power, and a high degree of temperature consisting of strontium nitrate to 60% and boron 10 to 40%.

3. A pyrotechnic mixture for use in an ordnance missile consisting of 85 to 60% of strontium nitrate and from 15 to 40% of boron.

4. A pyrotechnic composition consisting of 60% strontium nitrate and 40% of boron.

References Cited in the file of this patent UNITED STATES PATENTS 528,515 Hensley Oct. 30, 1894 2,410,801 Audrieth Nov. 12, 1946 FOREIGN PATENTS 27,341 Great Britain of A. D. 1908 

1. A PYROTECHNIC MIXTURE FOR USE IN AN INCENDIARY DEVICE CONSISTING OF FROM 80 TO 65% OF STRONTIUM NITRATE AND FROM 20 TO 35% OF BORON. 